Assessing Fitness Costs and Phenotypic Instability of Fentin Hydroxide and Tebuconazole Resistance in Venturia effusa

Sensitivity monitoring of Venturia effusa, cause of pecan scab, has revealed insensitivity to fentin hydroxide and tebuconazole, but recent research indicates that the insensitivity to fentin hydroxide is not stable. A study was undertaken to determine if a fitness cost may be responsible for this i...

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Veröffentlicht in:Plant disease. - 1997. - 103(2019), 9 vom: 19. Sept., Seite 2271-2276
1. Verfasser: Standish, Jeffrey R (VerfasserIn)
Weitere Verfasser: Brenneman, Timothy B, Brewer, Marin T, Stevenson, Katherine L
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2019
Zugriff auf das übergeordnete Werk:Plant disease
Schlagworte:Journal Article demethylation inhibitor fitness penalty fungicide resistance organotin triphenyltin hydroxide Organotin Compounds Triazoles tebuconazole 401ATW8TRW KKL46V5313
Beschreibung
Zusammenfassung:Sensitivity monitoring of Venturia effusa, cause of pecan scab, has revealed insensitivity to fentin hydroxide and tebuconazole, but recent research indicates that the insensitivity to fentin hydroxide is not stable. A study was undertaken to determine if a fitness cost may be responsible for this instability. In this study, experiments were conducted to evaluate fitness components and phenotypic stability of insensitivity of V. effusa to fentin hydroxide and tebuconazole. Conidial production, conidial germination, microcolony growth, sensitivity to osmotic stress, and sensitivity to oxidative stress in the absence of fungicide were compared for isolates with differing sensitivities to both fungicides. Percent conidial germination decreased linearly with increasing fentin hydroxide insensitivity, and microcolony growth on 1.0 mM H2O2 decreased linearly with increasing tebuconazole insensitivity. Stability of resistance was assessed on concentrations of 1.0, 3.0, and 10 µg/ml of both fungicides prior to and after five transfers on non-fungicide-amended medium. Tebuconazole insensitivity was stable after transfers, but fentin hydroxide insensitivity on 1.0 and 3.0 µg/ml decreased significantly after transfers, indicating instability. Here we provide evidence that in V. effusa tebuconazole insensitivity is stable and fentin hydroxide insensitivity is not. These results suggest that fentin-hydroxide-resistant V. effusa isolates have reduced conidial viability compared with sensitive isolates, which may allow the population to regain sensitivity in the absence of this frequently used fungicide
Beschreibung:Date Completed 24.09.2019
Date Revised 25.09.2019
published: Print-Electronic
Citation Status MEDLINE
ISSN:0191-2917
DOI:10.1094/PDIS-12-18-2292-RE